For various reasons associated in particular with greater comfort of use (softness, emollience and the like), current cosmetic compositions are usually in the form of an emulsion of the oil-in-water (O/W) type consisting of an aqueous-dispersing-continuous phase and an oily-dispersed-discontinuous phase, or of an emulsion of the water-in-oil (W/O) type consisting of an oily-dispersing-continuous phase and an aqueous-dispersed-discontinuous phase.
W/O emulsions are often stabilized with silicone elastomeric polymers. Silicone elastomeric polymers may have a nice cosmetic feel but W/O emulsions containing silicone elastomeric polymers are limited in terms of formula robustness and aesthetics.
Emulsions typically appear milky white due to the difference of refractive index between the internal phase and the external phase, leading to scattering of visible light. One approach to creating a translucent or transparent emulsion is to match the refractive index of the two immiscible phases. Generally, to match the refractive index, the refractive difference between the two immiscible phases is only allowed to be about ±0.001-0.005. One drawback of refractive index matching is that the matching requires a large amount of adjusters such as glycols or fluorocarbons, which may result in an undesirable tacky residue or feel when applied to the skin.
Another approach to creating a translucent or transparent emulsion is to reduce the emulsion droplet size such that the emulsion droplet size becomes smaller than one-quarter the wavelength of visible light (generally less than about 100 nm), resulting in a nanoemulsion. Drawbacks of obtaining nanoemulsion include a high cost due to the high energy and high temperatures required for processing to obtain the small droplet size to create the nanoemulsion. Generally heat or increased pressure is required to create nanoemulsions. Process temperature usually exceeds about 75° C., while pressure usually exceeds 1500 bars with at least 7 passages.
Therefore, it is desirable to provide a translucent cosmetic composition in the form of an oil-in water emulsion that has a nice cosmetic feel that does not suffer from one or more of the above drawbacks.